Since I haven't yet read/seen any posts about success stories on the subj (except for someone who claimed he added a usb bt dongle, but didn't support it by any tech info/pics), I'm getting ready to perform a first surgery on my C1K. Time permitting, I hope to do it sometime next week (maybe on July 4th holiday weekend).

Here's a few thoughts I have on the subj:- There's a ffuart wired up to a port on the back of the C1K (so-called sharp i/o port) that has all modem control lines. I'm leaving it as a last resort (if everything else fails), since I want to retain it for rs232 comm.- There's a btuart in PXA270 that has CTS/RTS control lines, but it's unknown if Sharp traced it on PCB. I would guess that it would make sense to have it traced just in case, i.e. planning for future models with built-in BT, but with Sharp you never know...- Well, it leaves us with stuart that is wired up to IRDA transmitter/diode, but doesn't have any control lines, so hardware flow control is not possible.

If btuart lines can't be traced, either rs232 or irda has to go. Personally, I don't use IRDA myself, so for me the choice is clear. But not having hardware flow control leaves us with a challange of fighting high interrupt latency of bloated Sharp's kernel to avoid fifo overruns. I took a look at Sharp's serial driver, and as usual with sharp it's ... well, not good. I had troubles with overruns even at modest speeds. Now, the good thing is that it;s Intel PXA270, not Sharp's proprientary hardware, so full tech specs are available. I spend a few hours on "unsharp'ing" the serial driver, so now it seems to run ok. I tested it @ 460800 and not getting overruns anymore. I still need to test it @ 921600 and implement suspend/resume hooks, maybe add some hooks to front LED to show activity, etc.

Anyway, just thought it would be useful to have a dedicated thread where we all can share tech info and success stories. Please feel free to contribute... and I'll update you on status of my surgery.-albertr

C1K has two LEDs, both are software controlled, AFAIK. One is charging, another is email. I'm thinking of using the email LED to blink on uart activity.

As far as module's power consumption goes, I'll need to find +3.3V or +5V (both would work in my case) with peak load of approx. 50-80mA (@ 3.3V). I'm not sure how IRDA transmitter power is controlled and what's its peak load capability. If it can supply 80mA and can be software controlled (via some GPIO pin?) I can use it. Otherwise I'll need to find other source. If anyone has ideas on what it could be, please let me know...

On a side note, was not able to get it work @ 921600 baud, so I settled on 460800 for now.-albertr

As far as module's power consumption goes, I'll need to find +3.3V or +5V (both would work in my case) with peak load of approx. 50-80mA (@ 3.3V). I'm not sure how IRDA transmitter power is controlled and what's its peak load capability. If it can supply 80mA and can be software controlled (via some GPIO pin?) I can use it. Otherwise I'll need to find other source. If anyone has ideas on what it could be, please let me know...

As a power source, have a look at the CF ports. It should have 3.3V and maybe also 5V available.

I have developed a backlight upgrade for the HP 200LX which needed quite some current at 5V. I used the 5V source of the PCMCIA port of the 200LX and a GPIO line of the processor to control power using a software driver with hotkey (see http://www.daniel-hertrich.de/backlight/install ).

The "power switch" was in that case built into the backlight driver chip, which I could directly connect the GPIO pin to.

For the Zaurus BT project, a simple trnsistor circuit or something like that could combine a GPIO line for switching and the power source to a GPIO-controlled high-current power source.